Vasyl Mykhaylovych Ivanchuk, also transliterated as Vasyliy or Vasyl (Ukrainian: Василь Михайлович Іванчук; Russian: Васи́лий Михайлович Иванчу́к) (born March 18, 1969 in Kopychyntsi, Ukrainian SSR), is a Ukrainian chess grandmaster.
Ivanchuk has been a leading player in the world since 1988, ranking as high as No. 2 on the official FIDE Elo rating list (July 1991, July 1992, October 2007) and No. 1 briefly on the unofficial live rating updates from September 10–12, 2008. Ivanchuk often has erratic results, dropping as low as 30th in July 2009 before returning to the top ten in the next list.
Ivanchuk was the 2007–2008 World Blitz Chess champion, and won the Amber blindfold and rapid chess championship in 1992 and 2010.
In 2011, by the decree of the President of Ukraine, Ivanchuk was awarded the Order of Prince Yaroslav the Wise IV degree.